随便 (suí biàn): ตามความปรารถนา

What do you want to eat? Whatever.

He casually put on any clothes and went out.

Don't throw trash anywhere.

Whether you come or not, it's up to you.

Sit wherever you like, don't be polite.

He is dressed casually, without a tie.

No matter what you say, I don't care.

You can take these books as you please; no need to return them.